A display device with high brightness and a maximum visible area has become an important development direction of the display device. Usually, to achieve the high brightness for a liquid display device, luminance of the backlight source needs to be increased. Generally, the increase in luminance of the backlight source depends on an increase in the number of light sources (e.g. LEDs). Nevertheless, the increase in the number of the light sources would inevitably cause an increase in heat generated by the light sources, which requires that the backlight source has a structure with a good heat dissipating capability. In a structure of the backlight source in a related art, components such as a light guide plate and a reflecting layer may be deformed irreversibly because of the heat, resulting in damage to the backlight source.